physics 1 midterm study guide ch2

B) 26.0 m, 6.0 m

1) An object moves 15.0 m north and then 11.0 m south. Find both the distance traveled and the magnitude of the displacement vector. A) 6.0 m, 26.0 m B) 26.0 m, 6.0 m C) 26.0 m, 26.0 m D) 6.0 m, 6.0 m

C) The displacement is either less than or equal to the distance traveled.

1) Suppose that an object travels from one point in space to another. Make a comparison between the displacement and the distance traveled. A) The displacement is either greater than or equal to the distance traveled. B) The displacement is always equal to the distance traveled. C) The displacement is either less than or equal to the distance traveled. D) The displacement can be either greater than, smaller than, or equal to the distance traveled.

D) 5.3 km/h

10) A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average speed? A) 0 km/h B) 0.09 km/h C) 4.5 km/h D) 5.3 km/h

A) 0 km/h

11) A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, then 1.0 km north, then 1.0 km west to return to its starting point. This trip takes 45 min. What was the bear's average velocity? A) 0 km/h B) 0.09 km/h C) 4.5 km/h D) 5.3 km/h

B) 190 mi

12) You are driving home on a weekend from school at 55 mi/h for 110 miles. It then starts to snow and you slow to 35 mi/h. You arrive home after driving 4 hours and 15 minutes. How far is your hometown from school? A) 180 mi B) 190 mi C) 200 mi D) 210 mi

B) 89 km/h

13) A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this trip? A) 84 km/h B) 89 km/h C) 90 km/h D) 91 km/h

B) 88 km/h

14) A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip? A) 85 km/h B) 88 km/h C) 90 km/h D) 92 km/h

B) 270 mi/h

15) An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the trip? A) 260 mi/h B) 270 mi/h C) 275 mi/h D) 280 mi/h

B) 3.0 m

16) In a 400-m relay race the anchorman (the person who runs the last 100 m) for team A can run 100 m in 9.8 s. His rival, the anchorman for team B, can cover 100 m in 10.1 s. What is the largest lead the team B runner can have when the team A runner starts the final leg of the race, in order that the team A runner not lose the race? A) 2.0 m B) 3.0 m C) 4.0 m D) 5.0 m

A) 10 km/h-s

17) A car decelerates uniformly and comes to a stop after 10 s. The car's average velocity during deceleration was 50 km/h. What was the car's deceleration while slowing down? A) 10 km/h-s B) 8.0 km/h-s C) 5.0 km/h-s D) 4.0 km/h-s

C) 4.0 s

18) An airplane increases its speed from 100 m/s to 160 m/s, at the average rate of 15 m/s2. How much time does it take for the complete increase in speed? A) 17 s B) 0.058 s C) 4.0 s D) 0.25 s

D) 4.2 s

19) A car traveling 60 km/h accelerates at the rate of 2.0 m/s2. How much time is required for the car to reach a speed of 90 km/h? A) 15 s B) 30 s C) 45 s D) 4.2 s

D) 30 min

2) A boat can move at 30 km/h in still water. How long will it take to move 12 km upstream in a river flowing 6.0 km/h? A) 20 min B) 22 min C) 24 min D) 30 min

C) only when the velocity is constant

2) When is the average velocity of an object equal to the instantaneous velocity? A) always B) never C) only when the velocity is constant D) only when the velocity is increasing at a constant rate

C) 12 m/s

20) A cart starts from rest and accelerates at 4.0 m/s2 for 5.0 s, then maintain that velocity for 10 s, and then decelerates at the rate of 2.0 m/s2 for 4.0 s. What is the final speed of the car? A) 20 m/s B) 16 m/s C) 12 m/s D) 10 m/s

C) 45 m/s

21) A car travels at 15 m/s for 10 s. It then speeds up with a constant acceleration of 2.0 m/s2 for 15 s. At the end of this time, what is its velocity? A) 15 m/s B) 30 m/s C) 45 m/s D) 375 m/s

C) 66 m

22) A cart with an initial velocity of 5.0 m/s experiences a constant acceleration of 2.0 m/s2. What is the cart's displacement during the first 6.0 s of its motion? A) 10 m B) 55 m C) 66 m D) 80 m

A) -1.25 x 10^6

23) A bullet moving horizontally to the right (+x direction) with a speed of 500 m/s strikes a sandbag and penetrates a distance of 10.0 cm. What is the average acceleration, in m/s2, of the bullet? A) -1.25 x 10^6 B) -2.50 x 10^6 C) -1.25 x 10^3 D) -2.50 x 10^3

C) 42 m

24) A jet fighter plane is launched from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult? A) 16 m B) 24 m C) 42 m D) 84 m

C) 400 m

25) A car starting from rest moves with constant acceleration of 2.0 m/s2 for 10 s, then travels with constant speed for another 10 s, and then finally slows to a stop with constant acceleration of -2.0 m/s2. How far does it travel? A) 200 m B) 300 m C) 400 m D) 500 m

C) 12 m/s2

26) A car goes from 40 m/s to 80 m/s in a distance of 200 m. What is its average acceleration? A) 8.0 m/s2 B) 9.6 m/s2 C) 12 m/s2 D) 24 m/s2

C) 25 m

27) An object starts from rest and undergoes uniform acceleration. During the first second it travels 5.0 m. How far will it travel during the third second? A) 5.0 m B) 15 m C) 25 m D) 45 m

B) 39 m

28) An object is moving in a straight line with constant acceleration. Initially it is traveling at 16 m/s. Three seconds later it is traveling at 10 m/s. How far does it move during this time? A) 30 m B) 39 m C) 48 m D) 57 m

C) 21 s

29) A car starts from rest and accelerates uniformly at 3.0 m/s2. A second car starts from rest 6.0 s later at the same point and accelerates uniformly at 5.0 m/s2. How long does it take the second car to overtake the first car? A) 12 s B) 19 s C) 21 s D) 24 s

A) 25 m/s

3) 55 mi/h is how many m/s? (1 mi = 1609 m.) A) 25 m/s B) 49 m/s C) 90 m/s D) 120 m/s

C) average acceleration.

3) A new car manufacturer advertises that their car can go "from zero to sixty in 8 s". This is a description of A) average speed. B) instantaneous speed. C) average acceleration. D) instantaneous acceleration.

(a.) 4.9 s (b.) 60 m

30) A car with good tires on a dry road can decelerate at about 5.0 m/s2 when braking. Suppose a car is initially traveling at 55 mi/h. (a.) How much time does it take the car to stop? (b.) What is the stopping distance?

C) 48 m

32) An object is thrown upward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is 1.5 m/s2. What is the maximum height reached by the object? A) 8.0 m B) 18 m C) 48 m D) 144 m

A) 8.0 s

33) An object is thrown upward with a speed of 12 m/s on the surface of planet X where the acceleration due to gravity is 1.5 m/s2. How long does it take for the object to reach the maximum height? A) 8.0 s B) 11 s C) 14 s D) 16 s

D) 12 s

34) An object is thrown upward with a speed of 15 m/s on the surface of planet X where the acceleration due to gravity is 2.5 m/s2. How long does it take for the object to return to where it is thrown? A) 6.0 s B) 8.0 s C) 10 s D) 12 s

B) 14 m/s

35) An object is thrown upward with a speed of 14 m/s on the surface of planet X where the acceleration due to gravity is 3.5 m/s2. What is the speed of the object after 8.0 s? A) 7.0 m/s B) 14 m/s C) 21 m/s D) 64 m/s

B) at least 4.9 cm

36) Human reaction time is usually greater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall before you catch it? A) at least 3.0 cm B) at least 4.9 cm C) at least 6.8 cm D) at least 9.8 cm

B) 9.8 m/s downward

37) A ball is thrown upward at a velocity of 19.6 m/s. What is its velocity after 3.00 s? A) 9.8 m/s upward B) 9.8 m/s downward C) zero D) 19.6 downward

C) 49 m/s

38) A bullet shot straight up returns to its starting point in 10 s. What is the initial speed of the bullet? A) 9.8 m/s B) 25 m/s C) 49 m/s D) 98 m/s

B) 7.35 s

39) A ball is thrown straight up with a speed of 36.0 m/s. How long does it take to return to its starting point? A) 3.67 s B) 7.35 s C) 11.0 s D) 14.7 s

D) increasing its velocity by 2.0 m/s in every second

4) An object moving in the +x axis experiences an acceleration of 2.0 m/s2. This means the object is A) traveling at 2.0 m in every second. B) traveling at 2.0 m/s in every second. C) changing its velocity by 2.0 m/s. D) increasing its velocity by 2.0 m/s in every second

C) 68.0 km/h

4) What must be your average speed in order to travel 350 km in 5.15 h? A) 66.0 km/h B) 67.0 km/h C) 68.0 km/h D) 69.0 km/h

D) 70 m

40) A ball is thrown downward from the top of a building with an initial speed of 25 m/s. It strikes the ground after 2.0 s. How high is the building? A) 20 m B) 30 m C) 50 m D) 70 m

(a.) 3.1 s (b.) 46 m (c.) 11 m/s

41) A ball is thrown straight up with a speed of 30 m/s. (a.) How long does it take the ball to reach the maximum height? (b.) What is the maximum height reached by the ball? (c.) What is its speed after 4.2 s?

(a.) 3.06 s (b.) 45.9 m (c.) 0.995 s and 5.13 s (d.) One value for the ball traveling upward; one value for the ball traveling downward.

42) A foul ball is hit straight up into the air with a speed of 30.0 m/s. (a.) Calculate the time required for the ball to rise to its maximum height. (b.) Calculate the maximum height reached by the ball. (c.) Determine the time at which the ball pass a point 25.0 m above the point of contact between the bat and ball. (d.) Explain why there are two answers to part c.

B) 10 m/s

43) In Fig. 2-1, what is the velocity at t = 1.0 s? A) 0 B) 10 m/s C) 20 m/s D) -40 m/s

C) 20 m/s

44) In Fig. 2-1, what is the velocity at t = 2.5 s? A) 0 B) 10 m/s C) 20 m/s D) -40 m/s

A) 0

45) In Fig. 2-1, what is the velocity at t = 4.0 s? A) 0 B) 10 m/s C) 20 m/s D) -40 m/s

D) -40 m/s

46) In Fig. 2-1, what is the velocity at t = 5.5 s? A) 0 B) 10 m/s C) 20 m/s D) -40 m/s

B) 10 m/s

47) In Fig. 2-1, what is the average velocity from 0 to 4.0 s? A) 0 B) 10 m/s C) 20 m/s D) -40 m/s

A) 0

48) In Fig. 2-1, what is the average velocity from 0 to 6.0 s? A) 0 B) 10 m/s C) 20 m/s D) -40 m/s

D) 10 m/s2

49) In Fig. 2-2, what is the acceleration at 1.0 s? A) 0 B) 2.0 m/s2 C) -2.5 m/s2 D) 10 m/s2

C) 3.95 m/s

5) A runner ran the marathon (approximately 42.0 km) in 2 hours and 57 min. What is the average speed of the runner in m/s? A) 14.2 x 10^3 m/s B) 124 m/s C) 3.95 m/s D) 14.2 m/s

B) The car is decelerating, and its acceleration is negative.

5) Suppose that a car traveling to the East (+x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleration. A) The car is decelerating, and its acceleration is positive. B) The car is decelerating, and its acceleration is negative. C) The acceleration is zero. D) A statement cannot be made using the information given

A) 0

50) In Fig. 2-2, what is the acceleration at 3.0 s? A) 0 B) 2.0 m/s2 C) -2.5 m/s2 D) 10 m/s2

B) 2.0 m/s2

51) In Fig. 2-2, what is the average acceleration from 0 to 5.0 s? A) 0 B) 2.0 m/s2 C) -2.5 m/s2 D) 10 m/s2

C) -2.5 m/s2

52) In Fig. 2-2, what is the average acceleration from 0 to 8.0 s? A) 0 B) 2.0 m/s2 C) -2.5 m/s2 D) 10 m/s2

C) 60 m

53) In Fig. 2-2, what is the displacement from 0 to 8.0 s? A) 20 m B) 40 m C) 60 m D) 80 m

A) The car is decelerating, and its acceleration is positive.

6) Suppose that a car traveling to the West (-x direction) begins to slow down as it approaches a traffic light. Make a statement concerning its acceleration. A) The car is decelerating, and its acceleration is positive. B) The car is decelerating, and its acceleration is negative. C) The acceleration is zero. D) A statement cannot be made using the information given.

C) 5.88 x 10^12 mi

7) A ly (light year) is the distance that light travels in one year. The speed of light is 3.00 x 10^8 m/s. How many miles are there in a ly? (1 mi = 1609 m, 1 yr = 365 d.) A) 9.46 x 10^12 mi B) 9.46 x 10^15 mi C) 5.88 x 10^12 mi D) 5.88 x 10^15 mi

D) The acceleration must be equal to zero.

7) Suppose that an object is moving with a constant velocity. Make a statement concerning its acceleration. A) The acceleration must be constantly increasing. B) The acceleration must be constantly decreasing. C) The acceleration must be a constant non-zero value. D) The acceleration must be equal to zero.

A) no, and an example would be an object starting from rest

8) If the velocity of an object is zero, does it mean that the acceleration is zero? Support your answer with an example. A) no, and an example would be an object starting from rest B) no, and an example would be an object coming to a stop C) yes, because of the way in which velocity is defined D) yes, because of the way in which acceleration is defined

D) 80 m

8) If you are driving 72 km/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inattentive period? A) 18 m B) 20 m C) 40 m D) 80 m

D) zero.

9) If you run a complete loop around an outdoor track (400 m), in 100 s, your average velocity is A) 0.25 m/s. B) 4.0 m/s. C) 40,000 m/s. D) zero.

D) 4.4 h

A car travels 90 km/h. How long does it take for it to travel 400 km? A) 4.1 h B) 4.2 h C) 4.3 h D) 4.4 h

(a.) 15.0 s (b.) 225 m (c.) 30.0 m/s

At the instant a traffic light turns green, a car that has been waiting at the intersection starts ahead with a constant acceleration of 2.00 m/s2. At that moment a truck traveling with a constant velocity of 15.0 m/s overtakes and passes the car. (a.) Calculate the time necessary for the car to reach the truck. (b.) Calculate the distance beyond the traffic light that the car will pass the truck. (c.) Determine the speed of the car when it passes the truck.